“Michigan sends absentee ballots to 7.7 million people ahead of Primaries and the General Election,” Trump tweeted Wednesday. “This was done illegally and without authorization by a rogue Secretary of State. I will ask to hold up funding to Michigan if they want to go down this Voter Fraud path!”

It was not immediately clear what steps Trump could take to delay the funds, which come from coronavirus relief spending measures he has signed into law. Trump tagged his acting budget director, his chief of staff and the Treasury Department on the tweet.

Trump also threatened Nevada over mailed ballots, saying, “They can’t! If they do, “I think” I can hold up funds to the State.”

State of Nevada “thinks” that they can send out illegal vote by mail ballots, creating a great Voter Fraud scenario for the State and the U.S. They can’t! If they do, “I think” I can hold up funds to the State. Sorry, but you must not cheat in elections. @RussVought45@USTreasury

Trump has been very vocal about his opposition to voting by mail, claiming the practice is ripe for fraud although there is scant evidence of widespread wrongdoing with mail-in voting. Trump himself requested a mail ballot for Florida’s GOP primary last month and he has voted absentee in previous elections.

Trump says people should have to show up at polling stations and present ID to vote. But the coronavirus pandemic has upended that long-standing practice, with many voters fearful of waiting in line at polling stations and voting on machines that have been touched others.

Michigan spent $4.5 million in federal funds to mail absentee ballot applications to all 7.7 million registered voters for the August primary and November general election. Michigan is a crucial presidential battleground state that Trump, a Republican, narrowly won in 2016.

Michigan is among states hardest hit by the coronavirus pandemic, and Trump and the state’s Democratic governor, Gretchen Whitmer, occasionally have clashed over federal assistance during the crisis. Trump tweeted as the state grapples with its latest challenge, severe flooding in one central Michigan county after two dams failed.

Trump planned to visit Michigan on Thursday on a previously scheduled trip to tour Ford’s ventilator assembly plant in Ypsilanti.

Michigan’s Secretary of State Jocelyn Benson, a Democrat, announced the mailing Tuesday as part of the state’s efforts to confront voters’ concerns about the pandemic. Benson says the money came from $11.2 million it received from the federal government for elections.